JPH11214807A - Printed circuit board - Google Patents

Abstract

PROBLEM TO BE SOLVED: To lessen the length of joints disposed on a parting line and reduce the no. thereof, with holding the coupling strength between individual boards by forming a reinforcing layer on the inner surfaces of through-holes formed at the joints previously divided along a parting line to locate at desired regions. SOLUTION: A printed circuit board 1 is made to be divided into individual boards 2, 3 of the same specification by dividing in twos along a parting line X. On the printed circuit board 1 joins 11 are formed at a plurality of regions along the parting line X, and other parts are divided along a parting line to form slits 12. The individual boards 2, 3, are coupled to join by joints 11 only and disposed in ranges 17 near the joints where a circuit pattern 22 is not disposed, a plurality of through-holes 16 are formed along the parting line X at the joints 11 coupling the individual boards 2, 3 and hence only the coupled parts of the joints 11 can be easily broken and divided.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a printed circuit board having a circuit pattern formed on a plate-shaped insulator and divided into a plurality of pieces along a dividing line.

[0002]

2. Description of the Related Art Conventionally, a circuit pattern is formed on an insulator formed in a plate shape, and an electronic component is mounted thereon to constitute an electronic circuit. In order to standardize the transport size of the printed circuit board at the time of mounting and to reduce the cost of the printed circuit board, several sub-boards of printed circuit boards in a state of being incorporated in an electronic device or the like are arranged as individual boards. Are connected together to form a single printed circuit board as a whole. Thus, the printed circuit board formed as a whole as a whole forms a dividing line on the printed circuit board, and divides the printed circuit board into a plurality of individual boards along the dividing line. The division into individual substrates is performed after mounting various electronic components on a printed circuit board on which a circuit pattern is formed. In this case, in order to facilitate division into individual substrates, V
In many cases, a groove or a perforated joint is formed.

For example, as shown in FIG. 7, a printed circuit board 51 is divided into two along a dividing line X,
It is configured so that it can be divided into three. The printed circuit board 51 is formed with a plurality of joints 61 perforated along the dividing line X, and portions other than the joints 61 are divided along the dividing line X. The slits 62 are formed by being divided along X, and the individual substrates 52 and 53 are connected and connected only by the joints 61. Also, on each of the individual substrates 2 and 3,
The circuit patterns 72 constituting the electronic circuit are formed.

As described above, perforated joints 61.6
When the printed circuit board 51 formed with 1... Is divided into a plurality of individual boards 52 and 53 along the division line X, the joint portions 61 of the printed circuit board 51 are formed. The bent part is bent and broken, and is divided. However, stress accompanying bending and breaking is applied to the vicinity of the part where the joints 61 are formed. Due to this stress, perforated joints 61.6 formed on the printed circuit board 51 are formed.
1... Nearby circuit patterns, in particular, circuit patterns 72 that constitute signal circuits that are often formed with a narrow line width.
In addition, peeling or cracking may occur, and the reliability of the printed circuit board 51 may be reduced, or the circuit pattern 72 may be disconnected and conduction may not be obtained.

Therefore, conventionally, in order to prevent the circuit pattern 72 from peeling or cracking,
Are disposed away from the vicinity of the joints 61 as in the avoidance pattern 75 so that no stress is applied to the circuit pattern 72, or the circuit pattern 72 is connected to the joints 61. In the case where the circuit pattern 72 is disposed in the vicinity, the circuit pattern 72 is formed thick like the reinforcing pattern 76 to increase the strength so that peeling and cracking do not occur even when stress is applied to the circuit pattern 72.

[0006]

However, as described above, in order to prevent the circuit pattern 72 from peeling or cracking due to the stress generated by the division of the printed circuit board 51, the joint portion 61 and the connecting portion 61 are provided. 61... A circuit pattern 72 is disposed avoiding the vicinity,
Is thicker, the space in which the circuit pattern 72 on the individual substrates 2 and 3 can be formed is reduced, and the arrangement position and the circuit configuration of the circuit pattern 72 are greatly restricted.

Thus, a circuit similar to an electronic circuit that can be constructed when the avoidance pattern 75 and the reinforcement pattern 76 are not formed is replaced by a circuit similar to the electronic circuit.
When the printed circuit board 51 is formed on the printed circuit board, the size of the board is increased. Also,
In order to reduce the restriction by the avoidance pattern 75 and the reinforcement pattern 76, the joints 61, 61,.
The joints 61 may be formed by reducing the number of places where
.. Are reduced, the strength of the connecting portion between the individual substrates 2 and 3 is reduced, and the individual substrates 2 and 3 are separated before the electronic components are mounted, and the electronic component mounting apparatus There was a possibility that troubles such as being unable to be mounted on a vehicle would occur.

[0008]

The present invention uses the following means to solve the above-mentioned problems in the printed circuit board. That is, according to the first aspect, in a printed circuit board that is divided in advance along a dividing line and connected via a joint disposed at an arbitrary position of the dividing line, a through hole formed in the joint is provided. A reinforcing layer on the inner peripheral surface of the substrate.

According to a second aspect of the present invention, the joint portion is formed on a parting line where a circuit pattern formed on a printed circuit board is not arranged in the vicinity.

According to a third aspect of the present invention, a multilayer circuit pattern is formed on both sides of the printed circuit board or on both sides and the inside of the printed circuit board.

[0011]

Embodiments of the present invention will be described with reference to the accompanying drawings. FIG. 1 is an overall plan view showing a printed circuit board of the present invention, FIG. 2 is a sectional view taken along line AA in FIG. 1, FIG. 3 is a plan view showing a joint portion formed along a dividing line of the printed circuit board, 5 is a side sectional view, FIG. 5 is a plan view showing another embodiment of the joint portion, FIG. 6 is a side sectional view thereof, and FIG. 7 is an overall plan view showing a conventional printed circuit board.

The printed circuit board according to the present invention will be described.
First, FIG. 1 shows an example in which one printed circuit board is configured to be able to be divided into two individual boards. The printed circuit board 1 is formed by forming a circuit pattern 22 on a surface of a base material 26 formed in a plate shape and covering the circuit pattern 22 with a protective film 27 made of a solder resist, as described later. After an electronic circuit is configured by mounting components, the electronic circuit is divided into individual substrates 2 and 3 and separated, and the divided individual substrates 2 and 3 are incorporated into an electronic device such as a facsimile machine.

The printed circuit board 1 is divided into two parts along the dividing line X, so that the individual substrates 2
It is configured so that it can be divided into three. The printed circuit board 1 has joints 11 at a plurality of locations along the dividing line X.
Is formed, and portions other than the joint portions 11 are divided along the dividing line X to form slits 12, and the individual substrates 2 and 3 are connected only by the joint portions 11. It is connected. Then, the joints 11
Are located on the dividing line X and in the areas 17 and 17 where the circuit pattern 22 is not disposed in the vicinity. Also, a plurality of through-holes 16 are formed in the joint portion 11 connecting the individual substrates 2 and 3 with the dividing line X.
The joint portion 11 is formed in a so-called perforated shape.

As described above, when the printed circuit board 1 is divided along the dividing line X by forming the joint portions 11 formed in a perforated shape, the connecting portions of the joint portions 11 It is only necessary to break only the part, the area to be broken is reduced, the force required for breaking is reduced, and it is easy to divide. When the printed circuit board 1 is divided, stress is applied to the vicinity of the dividing line X.
The joints 11, 11 are formed on the base member to reduce the area to be broken, thereby suppressing the stress generated at the time of division.

The printed circuit board 1 may be configured to be divided into three or more parts, and the number of divisions is not limited.

As shown in FIG. 2, for example, the individual substrate 2 constituting the printed circuit board 1 of the present embodiment has a circuit pattern 22 formed on both sides of a base material 26 formed in a plate shape. Although it is configured as a so-called double-sided substrate having a protective film 27 formed on the surface, a so-called single-sided substrate having the circuit pattern 22 formed only on one surface of the base material 26 or a plurality of base materials 26 stacked on each other A so-called multilayer substrate in which the circuit patterns 22 are formed in multiple layers between the base materials 26 and on both surfaces may be used.

The substrate 26 is made of an insulating material such as a so-called glass epoxy plate formed by impregnating glass fibers with an epoxy resin, or a so-called paper phenol plate formed by impregnating paper with a phenol resin. It consists of. The circuit pattern 22 is made of a conductor such as copper, and is formed by, for example, etching a substrate 26 having a copper foil adhered to the surface, or by plating the surface of the substrate 26. Or Electronic circuits such as a signal circuit and a power supply circuit are formed on the individual substrate 2 by the circuit pattern 22 formed in this manner. Further, a protective film made of an insulator is formed on the surface of the circuit pattern 22 to protect the circuit pattern 22 against external impact, corrosion and the like.

Further, for example, a mounting hole 28 is formed in a mounting portion of the electronic component on the individual substrate 2, and a land portion 29 is formed without forming a protective film 27 around the mounting hole 28. Then, the terminal part of the electronic component is inserted into the mounting hole 28, and the terminal part of the electronic component is connected to the circuit pattern 22 by soldering or the like in the land part 29, thereby mounting the electronic component on the individual substrate 2. It is configured to be.

Further, a through-hole 30 is formed at an appropriate position on the individual substrate 2, and a conductor layer 31 is formed on the inner peripheral surface of the through-hole 30. 2 form a through hole 15 for electrically connecting the circuit pattern 22 formed on one surface to the circuit pattern 22 formed on the other surface.
The conductor layer 31 of the through hole 15 is formed by plating a conductor such as copper on the inner peripheral surface of the through hole 30. The individual substrate 3 has the same configuration as the individual substrate 2 described above.

Next, the main part of the present invention will be described. FIGS. 3 and 4 show a joint portion 11 that connects the individual substrates 2 and 3 that are divided from each other. As described above, the joint portions 11 are formed on the dividing line X and have a plurality of through holes 16. That is, the joint portion 11 includes a plurality of through holes 16 on the dividing line X and a plurality of connection joints 32.
Are formed in a perforated shape in which the individual boards 2 and 3 are joined alternately.
. Are connected intermittently.

A reinforcing layer 33 is formed on the inner peripheral surface of the through hole 16. The reinforcing layer 33 is formed, for example, by plating a conductor such as copper on the inner peripheral surface of the through hole 16, and forms the conductor layer 31 formed in the through hole 30 of the through hole 15 shown in FIG. It is formed by the same material and method.

As described above, by forming the reinforcing layer 33 on the inner peripheral surface of the through hole 16 of the joint portion 11 connecting the individual substrates 2 and 3, the connection joints 32 of the joint portion 11 are formed.
.. Are strengthened, and the mechanical connection strength of each joint portion 11 can be increased. By increasing the connection strength of each joint 11, the number of joints 11 arranged on the dividing line X can be reduced while maintaining the connection strength between the individual boards 2 and the individual boards 3, .. Can be reduced to reduce the length of the joint portion 11. That is, the connection strength of each joint portion 11 is higher than the case where the reinforcing layer 33 is not formed on the inner peripheral surface of the through hole 16, so the number of the joint portions 11 and the connection joints 32. Even if you reduce the number of
The connection strength between the individual substrates 2 and 3 can be kept equal.

For example, in the printed circuit board 51 shown in FIG. 7, the joint portions 61 having no reinforcing layer formed in the through holes are arranged at four positions on the dividing line X, and the individual substrates 52 and 53 are separated from each other. Are linked. On the other hand, in the printed circuit board 1 of the present embodiment, as shown in FIG.
6. The joint part 11 having the reinforcing layer 33 formed on the inner peripheral surface
Although the individual substrates 2 and the individual substrates 3 are connected to each other by being arranged at the two upper positions, the coupling strength between the individual substrates 52 and 53 and the coupling strength between the individual substrates 2 and 3 are equal. Is configured.

As described above, by reducing the number of joints 11 to be arranged while maintaining the necessary connection strength, the joints 1
1, the arrangement of the circuit pattern 22 avoiding the vicinity of 1, and the formation of the circuit pattern 22 thicker can be reduced.
The effective use space increases, and the circuit pattern 2
Thus, restrictions on the arrangement position and circuit configuration of the printed circuit board 2 can be considerably reduced, and the degree of freedom in designing the circuit pattern 22 of the printed circuit board 1 can be increased. In addition, by forming the reinforcing layer 33 formed on the inner peripheral surface of the through hole 16 by using the same material and method as the conductor layer 31 formed on the through hole 15, the conventional through hole 15 is formed. In the step of forming the conductor layer 31, at the same time, the reinforcing layer 33 is formed on the inner peripheral surface of the through hole 16 formed in the joint portion 11.
Can be formed, so that the number of manufacturing steps and manufacturing costs do not increase.

In this embodiment, the reinforcing layer 33 is formed in the through hole 16 formed in the joint portion 11 of the printed circuit board 1 formed on the double-sided board to improve the connection strength of the joint portion 11. However, the through hole 16 in the joint portion of the printed circuit board configured as a multilayer board also
The connection strength can be improved by forming a reinforcement layer configured in the same manner as the reinforcement layer 33 of FIG. Also, for a through-hole formed in a joint portion of a printed circuit board formed on a single-sided board, a reinforcing layer that enhances the joint strength of the joint portion may be formed to improve the joint strength of the joint portion. It is possible.

The joint section 11 can also be configured as follows. That is, as shown in FIGS. 5 and 6, the joint portion 41 formed on the dividing line X has a plurality of through holes 42.
42 are formed. That is, the joint 41 is
.. And a plurality of coupling joints 45 are alternately formed on the dividing line X in a perforated shape. A reinforcing layer 43 is formed on the inner peripheral surface of the through hole 42. The reinforcing layer 43
For example, it is formed by plating a conductor such as copper on the inner peripheral surface of the through hole 42, and is formed of the same material and method as the conductor layer 31 formed in the through hole 15.

The reinforcing layers 43 formed on the inner peripheral surface of each through hole 42 are also formed on both surfaces of the base material 26 and are integrally connected. In this way, the reinforcing layers 43 formed in the through holes 42 are connected to each other on the surfaces of the connection joints 45, 45, so that the connection strength of the joint portion 41 is increased. This can be further improved as compared with the case of the connecting portion 11. This can further reduce restrictions on the arrangement position and the circuit configuration that the circuit pattern 72 receives.

[0028]

According to the present invention, the printed circuit board having the above-described configuration has the following effects.
First, as described in claim 1, by forming a reinforcing layer on the inner peripheral surface of the through hole formed in the joint portion, the joint portion disposed on the dividing line while maintaining the connection strength between the individual substrates. And the joint length could be reduced. As a result, it is possible to reduce the necessity of arranging the circuit pattern avoiding the vicinity of the joint portion or to increase the thickness of the circuit pattern. Can be considerably reduced, and the degree of freedom in designing the circuit pattern of the printed circuit board can be increased.

Further, since the joint portion is formed on a dividing line where the circuit pattern formed on the printed circuit board is not disposed in the vicinity, the circuit pattern is avoided while avoiding the vicinity of the joint portion. There is no need to arrange or make the circuit pattern thicker, and it is possible to remove restrictions on the arrangement position and circuit configuration that the circuit pattern receives, thereby increasing the degree of freedom in designing the circuit pattern of the printed circuit board. Could be even wider.

Furthermore, since the circuit pattern is formed in multiple layers on both sides of the printed circuit board or on both sides and inside of the printed circuit board, a reinforcing layer formed in the through hole of the joint portion may be provided. The circuit pattern can be formed by the same material and method as the conductor layer of the through hole formed on the printed circuit board having both sides or a multilayer formed,
In the step of forming the conductor layer of the through hole, the reinforcing layer can be formed on the inner peripheral surface of the through hole formed in the joint at the same time, without increasing the number of manufacturing steps and manufacturing cost of the printed circuit board, The degree of freedom in designing the circuit pattern of the printed circuit board can be increased.

[Brief description of the drawings]

FIG. 1 is an overall plan view showing a printed circuit board of the present invention.

FIG. 2 is a sectional view taken along line AA in FIG.

FIG. 3 is a plan view showing a joint formed along a dividing line of the printed circuit board.

FIG. 4 is a side sectional view of the same.

FIG. 5 is a plan view showing another embodiment of the joint portion.

FIG. 6 is a side sectional view of the same.

FIG. 7 is an overall plan view showing a conventional printed circuit board.

[Explanation of symbols]

 X Dividing line 1 Printed circuit board 2.3 Individual board 11 Joint section 12 Slit 15 Through hole 16 Through hole 17 Range (no circuit pattern is arranged near) 22 Circuit pattern 31 Conductive layer 32 Connection joint 33 Reinforcement layer

Claims (3)

[Claims] 1. A printed circuit board which has been divided in advance along a dividing line and connected via a joint disposed at an arbitrary position of the dividing line, an inner periphery of a through hole formed in the joint. A printed circuit board having a reinforcing layer formed on a surface. 2. The printed circuit board according to claim 1, wherein the joint portion is formed on a dividing line where a circuit pattern formed on the printed circuit board is not arranged in the vicinity. 3. The printed circuit board according to claim 1, wherein a multilayer circuit pattern is formed on both sides of the printed circuit board, or on both sides and inside of the printed circuit board.